At age 23, Lindsay Avner took charge of her genetic fate by electing to have her healthy breasts removed before cancer could strike first. Six years later, the North Side woman has zero regret, she said.

"I feel so fortunate to have had this opportunity that generations of women before me never had," said Avner, who was 11 when her mother was diagnosed with breast cancer, the same disease that claimed the lives of her grandmother, great-grandmother and others in her family tree.

So, when Avner tested positive for the gene mutation that increased her odds of becoming another victim, she opted for a double mastectomy. She was heralded as a "pioneer" by her physician at Memorial Sloan Kettering Cancer Center in New York.

The decision to removedisease-free breasts is not nearly as controversial as it was back in 2006, when Avner had surgery. Many more women have disclosed that they have made the same tough decision either because of hereditary factors or finding early stage cancer in one breast, including a recent Miss America contestant.

Still, some clinicians think the pendulum has swung too far for women who do not have the gene mutation, with more of them opting for double mastectomies as the first line of defense. The increase is attributed to a number of factors, including a barrage of health campaigns that cause some women to overestimate risks and the misconception that removing both breasts guarantees you will never have breast cancer, experts said.

The rate of prophylactic — or preventive — mastectomy among U.S. women with cancer in one breast rose by about 150 percent from the late 1990s to the mid-2000s, according to multiple research studies.

Dr. Todd Tuttle, chief of surgical oncology at the University of Minnesota, said the trend shows no sign of slowing. A study by Tuttle published in the Journal of Clinical Oncology showed that about 1.8 percent of women with cancer in one breast had a double mastectomy in 1998. The percentage rose to 4.5 percent in 2003.

Tuttle, who continues to collect data on the subject, estimated that, 10 years later, 30,000 of the 200,000 women diagnosed each year with breast cancer will opt for a double mastectomy.

No one tracks how many women without cancer are choosing double mastectomy as a preventive measure, multiple researchers said. But anecdotally, doctors said more and more patients are asking about it, and many are following through with the procedure.

"It's very strange ... given how women fought so hard to conserve their breasts in the 1970s and '80s," Tuttle said. "Now, this seems to have gone in the total other direction."

About 1 in 8 U.S. women — or roughly 12 percent — will develop breast cancer. That's compared with 60 percent of women, such as Avner, who have inherited a harmful mutation in human genes that are known as tumor suppressors, according to the National Cancer Institute. Even without the genetic mutation, the breast cancer risk roughly doubles if there's a strong family history, such as a mother, sister or daughter who has been diagnosed with the disease.

Most preventive double mastectomies in the United States are being chosen by young women in the earliest stages of the disease, clinicians said. But this group has an excellent prognosis without a double mastectomy, said Dr. Seema Khan, professor of surgery at the Feinberg School of Medicine at Northwestern University, who like the other physicians interviewed wants patients to have a better understanding of the risks and benefits of the procedure.

"Women with unilateral breast cancer ... are coming into doctors' offices with disturbing frequency with the declared intent of undergoing a 'double mastectomy' so that they will 'never have to do this again,'" Khan wrote in a 2011 editorial in the Journal of Clinical Oncology.

"This has us really scratching our heads," she said last week. "There's no medical evidence that a bilateral mastectomy for this group increases length of life or survival rates ... or has any better outcomes than breast-conserving treatment and radiation," which is the standard.

Typically, a double mastectomy is a four-hour surgery versus one hour for a breast-conserving procedure, also called lumpectomy. It carries a significantly higher risk of surgical complications, such as infection and bleeding, than a single mastectomy, Khan said.

Many who undergo mastectomy in the unaffected breast do so because they mistakenly think they'll never have to worry about a recurrence. "That's a fallacy, because a malignancy can return on the skin of the (chest) wall," Khan said.

Several factors are driving the phenomena, including pervasive health campaigns that are helpful but also can provoke unnecessary anxiety. The risk that a woman with breast cancer will develop cancer in the second breast is about 5 percent over a 10-year period, but according to a University of Minnesota study, women estimate their chances at about 30 percent.

"Breast cancer awareness is a good thing, but women just get pounded with these messages all the time," Tuttle said. "When the NFL has 'pink days,' you know it's over the top."